The present invention relates to an estimation device, an estimation method, and a recording medium.
In recent years, there has been developed a technology that detects vibration such as respiration of a subject in a contactless manner and estimates the detected vibration state in order to determine a health state of the subject. For example, JP 2006-263032A discloses a means for measuring vibration of a subject via an air pad equipped in the bedding used by the subject and calculating a cycle of the vibration of the subject from the measured signal. Also, JP 2014-014708A discloses a technology that calculates a cycle of vibration by identifying a boundary of a waveform of each one cycle of the vibration from a norm of a signal on a two-dimensional plane which is referred to as an IQ plane, with respect to an IQ signal (I: In-phase, Q: Quadrature-phase) indicating vibration of a subject acquired by a Doppler sensor.